A time-series data is represented by the line y = a + bx . If the middle time period is taken as origin ( x = 0 ), and it is found that xy = 6 and x^2 - Mathematics MCQ Mathematics Mock Test - 10 2026 | ExamTest.live

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A time-series data is represented by the line y = a + b x . If the middle time period is taken as origin (\sum x = 0), and it is found that \sum x y = 6 and \sum x^{2} = 5, what is the value of ' b'?

Solution & Step-by-step Explanation

For a linear regression line y = a + b x with origin such that \sum x = 0, the parameter b is given by: b = \frac{\sum x y}{\sum x ^{2}} Given \sum x y = 6 and \sum x^{2} = 5 : b = \frac{6}{5} = 1.2 .

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A time-series data is represented by the line y = a + b x . If the middle time period is taken as origin (\sum x = 0), and it is found that \sum x y = 6 and \sum x^{2} = 5, what is the value of ' b'?

1

0.8

1.2

0.83

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